Method of making cores



Feb. 16 1926.

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Feb. 16 1926. A. ANDERSON METHOD OF MAKENG CORES Filed F813. 25, 1924 3 Sheeis-Sheec 5' INVENTOR.

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Patented Feb. .ie, 1926.

' ALEXANDER ANDERSON, OFYDETROIT, MICHIGAN, ASSIGNOR are EARL HOLLEY, 0F

- DETROIT, MICHIGAN.

METHOD OF MAKING- CORES.

Application filed February 25, 1924. Serial No. 694,918.

To all whom it mag concern:

Be it known that I, ALEXANDER ANnnnsoN, a citizen of the United States, residingat 9299 CascadeAvenue, Detroit, in the county of Wayne and State of Michigan, have invented certain new and useful Improvements in the Method of Making Cores, of which the following is a specification.

The object of this invention is to improve the method of making cores by means'of the sand blowing method. In this method, as

at present practiced, the core box, usually an aluminum casting, is placed under the receptacle from which the sand is blown, the core box pressed against the outlet from the sand receptacle and the air'pressure is then turned into the receptacle and the sand allowed to flow into the core box. The air if pressure is then relieved, the table supporting the core box lowered, the core box removed and rapped by hand, and finally the where the cores are dried and baked. .fore being baked the cores are very fragile clamps holding the two or more halves of the core box together removed and the core released.

The cores are then placed on core driers, which are supported on a frame in an oven and the resulting product is frequently defective due to the necessary handling, the percentage of spoilt cores being therefore large. lVhat is more important is that the cores are not true to dimensions so that frequently castings are spoilt.

The above very brief outline of the method of making cores now in use indicates that there is quite .a considerable amount of handling required which is largely eliminated in the following method. In addition there is a very considerable savingin money. The specific application of this invention, illustrated in the following specification, is an arrangement for making piston cores of the type corresponding to the coending application of Daniel H. Meloche, Serial N o. 591,725, filed October'2, 1922, in

- which the sprue passageis placed concentrically within the'core and the iron poured through the sprueinto gatsf feeding directly intothe piston bosses.

Figure 1 shows in elevation the core blowing machine with thecore' box. in the open position and with a core mounted on a sprue' print plate ready for removal. I ,Figure 2 s a cross sectional elevatlon on plane 2-2 of Figure 3 which shows a sprue print plate having two cores mounted on the prints.

. Figure 3 shows a partial plan view of the core box portion (in the closed position) of the core blowing machine illustrated in Figure 1.

Figure 4 shows a sectional elevation through the core box on the plane M of Figure. 3, which shows the core box in the base plate M extending from one side to the other of the machine. The base plate M in its turn is mounted on a platform N- which is raised and lowered by mechanism not shown.

The plates G H also carry guide pins 0 P. These guide pins slide in bushed holes in the casting Q, the plate A sliding in a recess or groove in the casting Q. Immediately .above the center of the two halves of the core box E D is located the sand container S provided with two air entrances and four sand outlets or nozzles T.

1 Above this is located the guillotine valve U and the sand hopper V. The wedge shaped pieces G C aresecu'red to the face of the sand container S so as to engage with the beveled portion of the plates G H. The

parts lettered S T U V are the essentialelements of a commercial core filling machine now being sold. This invention, however, relates to the means for o ening the core boxes and the handling 0 the cores in conjunction with a machine similar to that shown.

In Figure 3 the core box is shown in the closed position. The four elongated open ings IV WWW are the openings through -which the sand is fed into the core box from corresponding openings T in the bottom .ofthe sand container S. Gate prints X are shown located in the center of the piston bosses Y Y. These gate prints contact Will the core print B, as is clearly shown in Figure 4. Electric vibrators Z Z are mounted on the rear 'of the core box halves ED to enable the box to be opened without destroying the surfaces of the core.

In Figures 2 and 3the adjustable stop R is shown bolted to the casting Q and so arranged that the core prints BB can be located each exactly in the center of its corresponding portion of the core box.

Operations-The plate A, with the two core prints BB integral therewith, is slid in the recess in the casting Q, until the plate A contacts with the stop R which is correctly adjusted. Air pressure is then admitted to thepistons K L and the two halves D E of the core box closed. The platform N is then raised so that the openings WW WW come opposite the outlets T T T T of the sand container S, the wedges C C look ing the plates GH in position. The guil lotine valve U is then closed and compressed air is admitted to the chamber S. The sand in S is hereby ejected through T and the core box separates from ,the core leaving two piston cores mounted upon the core prints B B. The plate A is then drawn out of the slot in Q by hand and the two cores thereon placed on racks in an oven and the core dried and baked. After the core is dried and'baked the cores may be handled without any great care and are thus easily lifted-off the core prints B B.

Normally a core is placed upon a core drier, which is a perforated metal structure more or less conforming to the shape of the core, and which is intended to prevent the core distorting during the baking operation. Obviously these core driers themselves warp due to the repeated heating and cooling to which they are subjected, and frequently castings are spoilt because of these distortions. By the method outlined above, however, the core drier is eliminated. The core support A and core prints B B serve the double purposes of core prints and core support for drying-purposes.

But the great advantage that has been found in the practical operation of this method is that the cores do not sag, hence they may be held closely to dimensions and the machining allowances may therefore be reduced.

What I claim is:

The method of making sand cores, which consists in first mounting the two halves of a two-piece core box, which is open at the bottom, on horizontal guides, connecting pneumatic pistons to said core box halves, whereby the core box is opened and closed automatically, sliding a plate below the core box so as .to close the open end thereof, closing the two halves of the core box, blowing sand therein, opening the core box so as to leave the core on said plate, drying the core on the said plate, and finally rcmoving the core from the plate.

In testimony whereof I aflix my signature.

ALEXANDER ANDERSON.- 

